Hi Frank,
On Sun, 18 Jan 2026 at 10:43, Frank Wunderlich <[email protected]> wrote:
>
> From: Frank Wunderlich <[email protected]>
>
> Add a command for getting detected ram size with possibility to write
> to environment variable.
>
> example usage:
>
> BPI-R4> msize
> 4294967296
> BPI-R4> msize m
> 4096m
> BPI-R4> msize g
> 4g
> BPI-R4> msize g ramsize
> BPI-R4> printenv ramsize
> ramsize=4
> BPI-R4>
>
> board with 8GB ram:
>
> BPI-R4> msize
> 8589934592
> BPI-R4> msize m
> 8192m
> BPI-R4> msize g
> 8g
> BPI-R4> msize g ramsize
> BPI-R4> printenv ramsize
> ramsize=8
> BPI-R4>
>
> Signed-off-by: Frank Wunderlich <[email protected]>
> ---
> v2: add Kconfig entry
> ---
> cmd/Kconfig | 5 +++++
> cmd/mem.c | 32 ++++++++++++++++++++++++++++++++
> 2 files changed, 37 insertions(+)
Please can you add doc/usage/cmd/ and test/cmd
>
> diff --git a/cmd/Kconfig b/cmd/Kconfig
> index 5c611fb3016e..b82b17195b7e 100644
> --- a/cmd/Kconfig
> +++ b/cmd/Kconfig
> @@ -974,6 +974,11 @@ config CMD_RANDOM
> help
> random - fill memory with random data
>
> +config CMD_MEMSIZE
> + bool "memsize"
> + help
> + Get RAM via command for use in scripts.
I suggest a little more info in your help, so it is clear what the
command actually does.
> +
> config CMD_MEMTEST
> bool "memtest"
> help
> diff --git a/cmd/mem.c b/cmd/mem.c
> index d5d7ca2790bd..a067740d81c8 100644
> --- a/cmd/mem.c
> +++ b/cmd/mem.c
> @@ -33,6 +33,7 @@
> #include <linux/compiler.h>
> #include <linux/ctype.h>
> #include <linux/delay.h>
> +#include <linux/sizes.h>
>
> DECLARE_GLOBAL_DATA_PTR;
>
> @@ -711,6 +712,29 @@ static int do_mem_loopw(struct cmd_tbl *cmdtp, int flag,
> int argc,
> }
> #endif /* CONFIG_LOOPW */
>
> +#ifdef CONFIG_CMD_MEMSIZE
> +static int do_mem_size(struct cmd_tbl *cmdtp, int flag, int argc,
> + char *const argv[])
> +{
> + u64 memsize = gd->ram_size;
> +
> + if (argc > 1) {
> + if (!strcmp(argv[1], "m"))
> + memsize = (memsize + SZ_1M - 1) / SZ_1M;
> + else if (!strcmp(argv[1], "g"))
> + memsize = (memsize + SZ_1G - 1) / SZ_1G;
Can you do something like this?
memsize = ALIGN(memsize, SZ_1G)
> + if (argc > 2)
> + env_set_ulong(argv[2], memsize);
Normally U-Boot uses hex, so it would be worth mentioning that this
command doesn't. Or even provide a -d flag to select decimal?
> + else
> + printf("%lld%s\n", memsize, argv[1]);
> + } else {
> + printf("%lld\n", memsize);
> + }
> +
> + return 0;
> +}
> +#endif /* CONFIG_CMD_MEMSIZE */
> +
> #ifdef CONFIG_CMD_MEMTEST
> static ulong mem_test_alt(volatile ulong *buf, ulong start_addr, ulong
> end_addr,
> volatile ulong *dummy)
> @@ -1404,6 +1428,14 @@ U_BOOT_CMD(
> );
> #endif /* CONFIG_LOOPW */
>
> +#ifdef CONFIG_CMD_MEMSIZE
> +U_BOOT_CMD(
> + msize, 3, 1, do_mem_size,
> + "get detected ram size, optional set env variable with value",
> + "[m, g] [envvar]"
> +);
> +#endif /* CONFIG_CMD_MEMSIZE */
> +
> #ifdef CONFIG_CMD_MEMTEST
> U_BOOT_CMD(
> mtest, 5, 1, do_mem_mtest,
> --
> 2.43.0
>
Regards,
Simon
